Conventional flexible vacuum packaging for food products have heretofor utilized a container formed of a multi-layer sheet material, such as layers of plastic and foil. The materials forming layers of the container are selected in the interest of strength and maintaining the vacuum to prevent the ingress of air into the container. If the contents of the container or package is of a particulate nature, such as ground or whole bean coffee, the vacuumization of the package to seal the coffee therein results in an uneven, rough or pebblely appearance of the container's walls as they attempt to conform to the particulate surface the package's contents. Accordingly, it is a common practice of the prior art to overwrap the vacuum package in a bag or covering of paper. The overwrapping paper is printed to carry the desired graphics and text for the package. Since the paper covering or wrapping the package is not under vacuum it retains its generally smooth surface.
While the above packaging is suitable for its intended purposes, the paper overwrap must be applied to the vacuumized inner package on "off-line" or specially constructed equipment, thereby increasing manufacturing costs and expenses.
Another alternative embodiment to the foregoing packages is the utilization of a single, thicker walled container formed of many layers, e.g., four or more, so that when the flexible material wall conforms to the material within the package it takes less of the rough appearance of the enclosed product than is the case of thinner walled packages. While this alternative construction provides a package which is more aesthetically pleasing than the foregoing packages, it still leaves much to be desired.
Examples of prior art packaging formed of inner and outer packages spaced from one another by a gas space are shown in United Kingdom Patent Application GB-2085401 and French Pat. No. 2022831.